Along with the progress of the techniques of semiconductor integrated circuits that are required of higher integration and more enhanced functions, the semiconductor circuit elements have also been reduced in size while the number of those elements has remarkably increased. Furthermore, now that such semiconductor integrated circuits have come to be used widely in various fields, the number of those product types has also increased. Under such circumstances, in order to meet such demands of more miniaturizing, higher integrating, and flexible manufacturing techniques, it has also been required to carry out accurate inspections in processes, prevent generation of defective products, and grasp how those defective products are generated accurately so as to shorten the development period and keep high yields for forming those semiconductor integrated circuits. And recently, it is reported that the main factors that generate such defects of semiconductor integrated circuits have been changed from those to be caused at random by foreign matters, etc. to so-called systematic defects to be caused by imperfect resolution of exposure systems and reduction of process latitudes that cannot cope with the advancement of the miniaturization of semiconductor integrated circuits. As a result, in many cases, it has come to be possible to anticipate the manufacturing divisions that might generate such defects in the designing stage.
This means that there has occurred a problem that designed patterns cannot be delineated faithfully as they are designed due to the limited resolution in the optical lithography that delineates designed patterns actually on wafers and a phenomenon referred to as the optical proximity effects. And in order to avoid such problems, the optical proximity correction (OPC) technique that corrects the deformed patterns due to optical proximity effect has come to be employed in many cases. In spite of this, there are still some well-known problems, one of which is a problem that causes such defects to occur in specific shapes of specific patterns due to the specific shapes of those patterns, characteristics of the subject exposure system, and errors in the exposure conditions. Those defects are referred to as systematic defects and distinguished from conventional random defects that occur at random due to foreign matters, etc. as described above. And spots in which such systematic defects occur, particularly those that affect the production yield, are referred to as hot spots.
There are two conventional methods for inspecting defects of semiconductor integrated circuit patterns as described above; die to die method and die to data base method. The die-to-die method makes a comparison between patterns formed on two chips and if there is a difference between the pattern shapes, existence of a defect is determined. The die to data base method makes a comparison between an original design pattern and another actually formed pattern and if there is a difference between them, existence of a defect is determined. The former method is effective for inspecting random defects to be caused by foreign matters, etc. and employed widely. On the other hand, the latter method is usually employed for inspecting systematic defects to be caused by defects and errors that depend on mask manufacturing, exposure systems, and exposure methods. The latter method is also effective for inspecting hot spots.
On the other hand, the problem that the defect inspecting time increases significantly is considered to be very serious not only in the mask inspection, but also in the inspection of patterns on semiconductor integrated circuits. In order to cope with such problems, N. Miyazaki et al., “Design For Manufacturability Production Management Activity Report”, JEITA, DFM-Production Management Sub-committee in Semiconductor Manufacturing Technology Committee for Japan, Proc. of SPIE Vol. 6283, 628302-1, 2006 discloses a method that switches among defect inspection methods to narrow inspection objects by using design intents in a mask inspection process.